Mystery Worshipper: Carmel.The church: St Peter's College Chapel, Oxford, England.Denomination: Church of England, but for one night only, Greek Orthodox.The building: The chapel used to be the Church of St Peter le Bailey and is Victorian, but there have been others on this site. Inside it is a small, long college chapel built in mock medieval style with shiny new black and white timbered sloping roofs and arches on the pink walls. The nave has a long strip set with pleasing medieval-style red and yellow patterned tiles. All the windows are small, Gothic plain glass except for the altar window, which is quite modern stained glass.The neighbourhood: Like much of central Oxford, the sublime and ridiculous rub shoulders with ease. St Peter's is next to a Church of England church, across the road from a solicitors and Indian restaurant. This street is a well-known gathering place for alcoholics, but they don't usually bother outsiders.The cast: The Rt Rev Dr Kallistos Ware (Bishop of Diokleia and Lecturer in Eastern Christian Studies at Oxford University), Archimandrite Ephram Lash, and one other whose name I didn't catch, plus the Greek Byzantine Choir of Athens and St Peter's College Choir.

What was the name of the service?
The evening service of vespers according to the ancient Rite of the Great Church of Hagia Sophia, Constantinople. This rite was lost when the city was captured by the Ottoman Turks in 1453 and was only very recently rediscovered. Parts of it date back to the 8th century. With the aid of a Leventis grant, the choir were able to come to England and recreate it for us.

How full was the building?
It was packed. They ran out of chairs.

Did anyone welcome you personally?
I was greeted by a nice woman and her tiny daughter who shyly gave me a vespers book.

Was your pew comfortable?
There were modern padded chairs with scarlet cushions which were very comfortable. Latecomers got the pews which had been pushed to the sides of the chapel. Those arriving very late got no seats at all, but, as was explained to us, not sitting down is a natural part of a Greek Orthodox service. We were told that apart from standing when we were being directly blessed, it was up to us whether we did or not.

How would you describe the pre-service
atmosphere?
Busy and chatty. I would say that at least half the congregation were Greek. There was also a good sprinkling of clergymen and monastics from other Christian denominations in addition to students and everyone else.

What were the exact opening words of the
service?
"Good evening, ladies and gentlemen, and welcome to St Peter's College Chapel."

What books did the congregation use during the
service?
We had a neat little booklet printed specially for the occasion in English and Greek. It was rather thicker than I had expected, which gave me the first clue that this was likely to go on for some time.

What musical instruments were played?
None.

Did anything distract you?
Now and again a member of the congregation would drop something on the floor, which was so constructed that whatever it was landed with a bang.

Was the worship stiff-upper-lip, happy clappy, or
what?
Definitely formal. It began with a stately procession led by the Orthodox priests in golden robes and bearing a censer, followed by the choir, followed by those of us who had accepted the invitation to join them as they started in the garden. Most of us had stayed put, but we knew when it had begun by the sound of an odd rhythm being knocked out on a piece of wood, then from a distance the first sound of the chant. It was clear right from the start that this was going to be a formal occasion. We had, after all, been invited to imagine that this was being performed in St Sophia as had originally been intended.

Exactly how long was the sermon?
There was no sermon.

Which part of the service was like being in
heaven?
The music, without a doubt. There was a point when, after I had got lost for about the 12th time, I just closed my eyes and without any effort could imagine that I was, indeed, in Byzantium. There was nothing at all modern or Western about the singing. It was clearly formal but it did not yet have the rigidity of plainchant and had a good deal more of the East in its cadences, and I think the academic who introduced the service had said that it had originally come from a monastic community in Palestine. It was like opening a window and finding that the past had come to life. Some of it actually made the back of my neck prickle.

And which part was like being in... er... the other place?
Getting lost in the Greek text was one thing. There were parts when they didn't stick to the script, and I don't read Greek at all well anyway, so I quite often lost my place. The other thing was not having come prepared. Nobody had warned us about the length of the service. I had expected that it might be an hour or so, but after almost two hours we had only got halfway through and I realized that I could well be here nearly four hours. People kept leaving. I have to admit that I was one of them, but nature being what it is, I don't think I could have held out much longer.

What happened when you hung around after the service looking lost?
I didn't, I just went home.

How would you describe the after-service
coffee?
Not applicable.

How would you feel about making this church your regular (where 10 = ecstatic, 0 = terminal)?
1  I have to say that what I experienced of the service was fascinating. It was also quite interesting to compare it with the vespers I am used to. I would definitely go again sometime, but only if I knew how long it was all going to be so that I could be better prepared for it, have dinner first, etc.

Did the service make you feel glad to be a
Christian?
I'm not sure that it did. It raised a lot of thoughts in my mind about the split between the Orthodox and Catholic Churches and their relationship since then.

What one thing will you remember about all this in seven days' time?
The choir. The leader had a voice with the rich, singing quality of a good violin. He was backed up by an excellent choir, whose main function when not singing, interestingly, was to hum one low note to give an underlying droning effect a bit like the bottom note of an organ. There was nothing at all modern about this, and coming out into the evening sunlight was a bit of a jolt.

The Mystery Worshipper is sponsored by surefish.co.uk, the internet service provider from Christian Aid. By offering email services, special offers with companies such as amazon.co.uk and smile.co.uk, surefish raises more than £300,000 a year for Christian Aid's work around the world.

Click here to find out how to become a Mystery Worshipper. And click here if you would like to reproduce this report in your church magazine or website.